1. Field of the Invention
The present invention relates to the creation and maintenance of knowledge base systems, more particularly to the creation and maintenance of such systems in a multiuser environment, and more specifically to such systems for utilization in the context of health care.
2. Description Relative to the Prior Art
In the field of health care, as in many other fields involving the accumulation and application of masses of information, the use of artificial intelligence (AI) has been looked to as a means of automatic decision making. The field of health care, particularly, has seen a great deal of progress in this area, and many of the largest health care organizations routinely use some sort of computer implemented AI systems in the admission and treatment of patients.
A key part of such systems is the knowledge base, which is a repository of information in the field, or domain of interest. In such systems, information is generally organized in data trees in which it can be accessed by the user at any level. The data is generally arranged hierarchically, in a tree-like structure, so that more detail is derived as the user moves farther toward the tips of tree branches, with more generality toward the root of the tree. In addition to the tree-structured data organization, the knowledge base contains rules for dealing with the data, and for proceeding further down the tree based on the decisions made by the user. The data and associated rules are the key to using the knowledge base. It is obvious, however, that such a system will be no better than the data contained within the system.
It is clear that such systems require frequent updating of the knowledge base, both to correct pre-existing problems in the information, as well as adding new information as it becomes available. In the medical field, such updating has traditionally required highly trained medical personnel and computer programmers, and has been both time consuming and expensive.
The management of such updating adds a further layer of complexity, due to the problem of coordinating the activities of a number of different medical specialists working independently on the same knowledge base, and working at different stages of the updating process. As a result, there is the danger of inadvertently deleting or overwriting valid data.
A further problem is that of redundancy. Different medical specialists, specializing in entirely different areas of medicine, may nevertheless input information into the knowledge base which already exists in a different specialty area.
A still further problem involves the use of standard medical coding systems to describe medical conditions for medicare or other billing, clinical or financial reviews, and physician profiling. The use of these codes is essential for inclusion in the medical knowledge base system. Examples of these codes include CPT procedure codes, ICD9 diagnosis codes, ICD9-CM procedure codes, LOINC laboratory results codes, and SNOMED medical vocabulary codes. Selection of these codes for introduction into the knowledge base by the medical specialist is by no means obvious or self-explanatory. Two equally qualified specialists may select two different codes for the same condition.
Codes of this type are also used in the screening program (Autobook II) which uses the knowledge base generated and extracted by the present invention, whose preferred embodiment is a computer program entitled xe2x80x9cCDSxe2x80x9d. In Autobook II the codes are used for navigation purposes, directing the user to a particular section of the screening system via the code input.
A similar problem exists in regard to medical terminology. Two different specialists may use different terms and description for the same condition, treatment, etc. As a result, redundant information may be entered into the knowledge base without detection. Furthermore, much of the information in the knowledge tree may be redundant because of the repetition of common information in different parts of the database. For instance, sets of symptoms, such as nausea, blurred vision, dizziness, may occur as symptoms related to both neurological and gastrointestinal disease. The use of common libraries, as well as the use of a thesaurus, as in the present invention, address the problems of common lexicography and reduction of redundancy.
Finally, the method in which the contents of the knowledge tree are displayed has been problematic. Tradition favors the use of a tree-structure to show a knowledge tree. The tree structure is used throughout computer technology, in directory structures, for example. However, the tree structure often does not reveal characteristics of the data which may be obvious in other display formats.
CDS addresses all of these problems in a single development environment. The system first of all provides a graphic interface to the knowledge base which eliminates the need for programmers. Medical specialists with no programming experience or expertise may nonetheless update existing knowledge bases, or create new knowledge bases using the present system, which is implemented on a number of different platforms, including the personal computer (PC), and WEB browsers over the Internet.
Furthermore, CDS provides a multi-user environment in which system management, by means of data reservation and version control, allows multiple users to work independently in the same environment at the same time.
Standardization is facilitated by the inclusion of standard libraries, including table-look up and search facilities, which include constant redundancy checks.
CDS further provides a facility to extract versions of the knowledge in a number of different media. In addition to databases for the host system, the following outputs are provided:
a) a purely paper system, in which the knowledge base is converted into a written screening document in book form;
b) a database which is designed to be downloaded into an Internet-based system, accessible though a Web browser; and
c) a database which is designed to be downloaded into a hand-held computer system, using a compact operating system.
All of the above can be used by health care providers to implement medical expert systems or screening systems.
A general object of the current invention is to provide a system to create and modify knowledge bases for use in medical decision making. A specific object of this invention is to provide such a system in a multi-user development environment, allowing simultaneous access thereto. A further specific object of this invention is to provide such a system by means of a graphical interface, and using a variety of computer systems, including networked data communications systems, such as the Internet.
According to one aspect of the invention, a computer-program-implemented development system for creating and maintaining a medical-decision-making knowledge base which includes graphic means for displaying the knowledge base as a hierarchical multiplicity of nodes, each node related to one or more superior nodes. In addition the system includes means for displaying a title of text associated with each node, means for displaying a set of rules associated with each node, means for displaying references associated with each node, and means for displaying attributes associated with each node. There is included means for modifying each title, each set of rules, each reference, and each attribute. Means are provided for generating additional nodes related to any existing node, and means for deleting existing nodes. Means are further provided for modifying the relationship between any node and any other node. And finally, there is provided simulation means for verifying the knowledge base.
According to a further aspect of the invention, the knowledge base includes criteria topics, and further includes means to export packages of criteria topics in various forms. These forms include hard-copy printed form, databases configured to be downloaded into a suitably configured multi-user network, and databases configured to be downloaded into a hand-held computer. Furthermore, the formats of the export packages are dependent upon the attributes of the elements extracted.
According to still another aspect of the invention, the system further includes alternative formats in which to display the nodes, including a multiplicity of grids, and a multiplicity of branches in the form of a logic tree. Selection means allow the user to choose one of the alternative display formats, and there are means provided to display the hierarchy in either collapsed view or expanded view.
According to yet another aspect of the current invention, the development environment includes means for providing multi-user concurrent access to the environment, locking means for preventing interference between two or more users accessing the environment concurrently, and authorization means to prevent unauthorized access to the environment.
According to yet one more aspect of the current invention, the system further includes means for organizing the knowledge base into subsets, locking means to prevent more than one user to modify or delete a given subset at any one time; and means to notify users when a subset is locked.
According to still another aspect of the invention, the system further includes a hierarchical multiplicity of authorization levels, wherein each succeedingly lower level of authorization has more restrictions than the level above, and wherein the workflow is organized as a multiplicity of development stages. Each such stage has associated with it an authorization level, and each user is empowered to work at a particular authorization level or below. Within this system the stages of the development include definition, development, external review, internal review, pre-release, and release.
According to one more aspect of the invention, the knowledge base is organized in quanta of knowledge, a quantum comprising one or more nodes in a hierarchical relationship. The invention further includes means to organize the quanta in a library; and means to incorporate a quantum of knowledge at a given node of the knowledge tree by reference to its location in the library, without embedding a copy of the quantum therein.
According to a final aspect of the invention the system includes lexical checking means for establishing a uniform vocabulary throughout the knowledge base, wherein the vocabulary consists of a multiplicity of terms. This lexical checking includes a thesaurus of terms, library search means for locating a term within the thesaurus, and lexicon check means for establishing a standardized form of each term in the thesaurus. As a result the same form of the term is used throughout the knowledge base.